The AquaTop 200W Model GH-200 Submersible Heater will maintain a constant and stable temperature. This fully submersible glass heater offers simple and easy installation with the use of the included suction cups and can handle aquariums up to 50 gallons. With the highly visible temperature setting, the GH-200W is easy to set and adjust to the desired temperature with the use of the temperature adjustment knob. This powerful heater also has double insulation and is made from high quality insulated glass.